Location has always been a feature of mobile communications systems. With the advent of cellular radio system, inherent in the functions of the wireless communications networks (WCNs) were the concepts of cell, sector, paging area and service area. These radio coverage areas created within the WCN had a one-to-one correspondence to geographic areas, but were of limited use in enabling location-based services outside of the provision of communications between the mobile device and the WCN.
As part of the Personal Communications System (PCS) auction of 1994, the Federal Communications Commission, at the behest of public safety agencies, added a requirement for the location of wireless emergency services calls for cellular and PCS systems. The FCC's wireless Enhanced 9-1-1 (E9-1-1) rules were designed to improve the effectiveness and reliability of wireless 9-1-1 services by providing 9-1-1 dispatchers and public safety agencies with geographic location information on wireless 9-1-1 calls. Location accuracy varied from the E9-1-1 Phase I rules which required that the existing WCN developed location information be converted to a geographic representation and made available to public safety agencies. Phase II of the FCC E9-1-1 rules called for high-accuracy location of emergency services wireless calls. Eventually both network-based and mobile-based techniques were fielded to satisfy the E9-1-1 Phase II high accuracy location mandate.
As realized and noted in extensive prior art, the ability to routinely, reliably, and rapidly locate cellular wireless communications devices has the potential to provide significant public benefit in public safety and convenience and in commercial productivity. In response to the commercial and governmental demand a number of infrastructure-based, handset-based and network-based wireless location systems have been developed.
Infrastructure-based location techniques use information in use within the WCN to generate an approximate geographic location. Infrastructure-based location techniques include CID (serving Cell-ID), CID-RTF (serving cell-ID plus radio time-of-flight time-based ranging), CIDTA (serving cell-ID plus time-based ranging), and Enhanced Cell-ID (ECID, a serving cell, time-based ranging and power difference of arrival hybrid). Signals that generate the WCN information that is the precursor to infrastructure-based location may be collected at the handset or at the base station and delivered to a mobile location server which has databased knowledge of both the WCN topology and geographic topology.
Network-based location solutions use specialized receivers and/or passive monitors within, or overlaid on, the wireless communications network to collect uplink (mobile device-to-base station) signals, which are used to determine location and velocity of the mobile device. Overlay Network-based techniques include uplink Time-Difference-of-Arrival (TDOA), Angle-Of-Arrival (AOA), Multipath Analysis (RF fingerprinting), and signal strength measurement (SSM). Examples of network-based systems for the determination of locations for wireless mobile units are found in Stilp, et al., U.S. Pat. No. 5,327,144; Stilp, et al., U.S. Pat. No. 5,608,410; Kennedy, et al., U.S. Pat. No. 5,317,323; Maloney, et al., U.S. Pat. No. 4,728,959; and related art.
Mobile-device based location solutions use specialized electronics and/or software within the mobile device to collect signaling. Location determination can take place in the device or information can be transmitted to a landside server which determines the location. Device-based location techniques include CID (serving Cell-ID), CID-RTF (serving cell-ID plus radio time-of-flight time-based ranging), CIDTA (serving cell-ID plus time-based ranging), Enhanced Cell-ID (ECID, a serving cell, time-based ranging and power difference of arrival hybrid), Advanced-Forward-Link-Trilateration (AFLT), Enhanced Observed Time Difference (E-OTD), Observed-Time-Difference-of-Arrival (OTDOA) and Global Navigation Satellite System (GNSS) positioning. An example of a GNSS system is the United States NavStar Global Positioning System (GPS).
Hybrids of the network-based and mobile device-based techniques can be used to generate improved quality of services including improved speed, accuracy, yield, and uniformity of location. A wireless location system determines geographic position and, in some cases, the speed and direction of travel of wireless devices. Wireless location systems use uplink (device-to-network) signals, downlink (network-to-device) signals, or non-communications network signals (fixed beacons, terrestrial broadcasts, and/or satellite broadcasts). Network-based location solutions use specialized receivers and/or passive monitors within, or overlaid on, the wireless communications network to collect signaling used to determine location. Network-based techniques include uplink Time-Difference-of-Arrival (TDOA), Angle-Of-Arrival (AOA), Multipath Analysis (RF fingerprinting), and signal strength measurement (SSM). Hybrids of the network-based techniques can be used to generate improved quality of services including speed, accuracy, yield, and uniformity of location.
The use of collateral information supplied to the Wireless Location System from the Wireless Communications Network or off-line databased to enable or enhance location determination in network-based systems was introduced in Maloney, et al., U.S. Pat. No. 5,959,580; and further extended in Maloney, et al., U.S. Pat. Nos. 6,108,555 and 6,119,013. These and related following descriptions of the prior art for infrastructure-based location determination systems enable robust and effective location-determination performance when adequate measurement data can be derived or are otherwise available.
Since the advent of direct dial cellular telecommunications in 1984, and especially in the past decade, the cellular industry has increased the number of air interface protocols available for use by wireless telephones, increased the number of frequency bands in which wireless or mobile telephones may operate, and expanded the number of terms that refer or relate to mobile telephones to include “personal communications services,” “wireless,” and others. Also, data services, such as short-message-service (SMS), packet data services (for example the GPRS (GSM General Packet Radio Service) and IP Multimedia Subsystem (IMS) have proliferated as has the number and variety of voice, data and voice-data capable wireless devices.
The air interface protocols now used in the wireless industry include AMPS, N-AMPS, TDMA, CDMA, TS-CDMA, OFDM, OFDMA, GSM, TACS, ESMR, GPRS, EDGE, UMTS, WCDMA, WiMAX, LTE and others.
The term CDMA will be used to refer to the CDMA digital cellular (TIA/EIA TR-45.4 defined IS-95, IS-95A, IS-95B), Personal Communications Services (J-STD-008), and 3GPP2 defined CDMA-2000 and UMB standards and air interfaces. The term UMTS will be used to refer to the 3GPP specified Wideband-CDMA (W-CDMA) based Universal Mobile Telecommunications System, defining standards, and radio air interface. The term WiMAX is used to denote the IEEE defined 802.16, “Broadband Wireless”; 802.20, “Mobile Broadband Wireless Access”; and 802.22, “Wireless Regional Area Networks” technologies. The present invention also applies to the 3GPP defined Long-Term-Evolution (LTE) and the 3GPP LTE-Advanced system among others.
For further background information relating to the subject matter described herein, the reader may refer to the following patents and patent applications assigned to TruePosition Inc., or TruePosition's wholly owned subsidiary KSI: U.S. application Ser. No. 11/965,481 entitled “Subscriber Selective, Area-based Service Control” (the entirety of which is hereby incorporated by reference) which is a continuation-in-part of U.S. application Ser. No. 11/198,996 entitled “Geo-fencing in a Wireless Location System”, which is a continuation of Ser. No. 11/150,414, filed Jun. 10, 2005, entitled “Advanced Triggers for Location-Based Service Applications in a Wireless Location System”, which is a continuation-in-part of U.S. application Ser. No. 10/768,587, filed Jan. 29, 2004, entitled “Monitoring of Call Information in a Wireless Location System”, now pending, which is a continuation of U.S. application Ser. No. 09/909,221, filed Jul. 18, 2001, entitled “Monitoring of Call Information in a Wireless Location System,”, now U.S. Pat. No. 6,782,264 B2, which is a continuation-in-part of U.S. application Ser. No. 09/539,352, filed Mar. 31, 2000, entitled “Centralized database for a Wireless Location System,” now U.S. Pat. No. 6,317,604 B1, which is a continuation of U.S. application Ser. No. 09/227,764, filed Jan. 8, 1999, entitled “Calibration for Wireless Location System”, and U.S. Pat. No. 6,184,829 B1. Maloney, et al., U.S. Pat. No. 5,959,580; Maloney, et al., U.S. Pat. No. 6,108,555 and Maloney, et al., U.S. Pat. No. 6,119,013. Each of these is hereby incorporated by reference in its entirety.